mohanpedala

Table of Contents

• set -e, -u, -x, -o pipefail
• set -e
• set -x
• set -u
• set -o pipefail
• Setting IFS
• Original Reference

set -e, -u, -x, -o pipefail

sir-wabbit

// All of these compile in Dotty
// https://scastie.scala-lang.org/pLOvDSM8QNy7yNfvOhZ6xQ

class I0(i: Int) {
  def this() = this()
}

object I1 {
  val t : Int = 10
  def this(I1: Int) = { this() }

milessabin

import scala.language.{ higherKinds, implicitConversions }

object Defns {
  type Id[T] = T
  type ApplyTo[T] = { type λ[F[_]] = F[T] }
  type Const1[T] = { type λ[F[_]] = T }

  // Natural transform
  trait ~>[F[_], G[_]] {
    def apply[T](ft: F[T]): G[T]

sir-wabbit

package tracehash

final case class Cover(suffixLength: Int, fragmentLength: Int, coverSize: Int)

object `package` {
  def stackTraceHash(ex: Throwable): String = {
    val stackTrace = principalStackTrace(
      Slice.of(ex.getStackTrace),
      ex.isInstanceOf[StackOverflowError])

Chobbes

(defun retract-same-position ()
  "Call proof-retract-buffer, but retain position"
  (interactive)
  (push-mark)
  (proof-retract-buffer)
  (pop-mark))

gallais

Inductive T :=
  | Var : nat -> T
  | App : T -> T -> T.

Inductive S e : Prop := 
| def: forall R, (forall i, R i -> S i) ->
       (forall e', R e' -> S (App e e')) -> S e.

Definition def' :
  forall e, (forall e', S e' -> S (App e e')) -> S e.

Icelandjack

• Continued in Explicit Witnesses of Monoid Actions, Semigroup / Monoid / Applicative homomorphisms

Reddit discussion

My initial motivation for -XDerivingVia was deriving across isomorphisms.

Standard type-class encodings of isos turn out to be awkward due to overlap.

odersky

Principled Meta Programming for Scala

This note outlines a principled way to meta-programming in Scala. It tries to combine the best ideas from LMS and Scala macros in a minimalistic design.

• LMS: Types matter. Inputs, outputs and transformations should all be statically typed.

• Macros: Quotations are ultimately more easy to deal with than implicit-based type-lifting

• LMS: Some of the most interesting and powerful applications of meta-programming

troyfontaine

Methods of Signing Git Commits on MacOS

Last updated March 13, 2024

This Gist explains how to sign commits using gpg in a step-by-step fashion. Previously, krypt.co was heavily mentioned, but I've only recently learned they were acquired by Akamai and no longer update their previous free products. Those mentions have been removed.

Additionally, 1Password now supports signing Git commits with SSH keys and makes it pretty easy-plus you can easily configure Git Tower to use it for both signing and ssh.

For using a GUI-based GIT tool such as Tower or Github Desktop, follow the steps here for signing your commits with GPG.

gallais

module Subst1 where
open import Term

infixl 20 _-_
_-_ : {σ : Ty} → (Γ : Con) → Var Γ σ → Con
ε - ()
(Γ , σ) - vz = Γ
(Γ , τ) - vs x = (Γ - x) , τ